“Their achievement from 1941 to 1945 remains unprecedented. The United States on the eve of World War II had an army smaller than Portugal’s. It finished the conflict with a global navy larger than all of the fleets of the world put together. By 1945, America had a GDP equal to those of Germany, Japan, the Soviet Union, and the British Empire combined. With a population 50 million people smaller than that of the USSR, the United States fielded a military of roughly the same size.

America almost uniquely fought at once in the Pacific, Asia, the Mediterranean, and Europe, on and beneath the seas, in the skies, and on land. On the eve of the war, America’s military and political leaders, still traumatized by the Great Depression, fought bitterly over modest military appropriations, unsure of whether the country could afford even a single additional aircraft carrier or another small squadron of B-17s. Yet four years later, civilians had built 120 carriers of various types and were producing a B-24 bomber at the rate of one an hour at the Willow Run factory in Michigan. Such vast changes are still difficult to appreciate.

Certainly, what was learned through poverty and mayhem by those Americans born in the 1920s became invaluable in the decades following the war. The World War II cohort was a can-do generation who believed that they did not need to be perfect to be good enough. The strategic and operational disasters of World War II—the calamitous daylight bombing campaign of Europe in 1942-43, the quagmire of the Heurtgen Forest, or being surprised at the Battle of Bulge—hardly demoralized these men and women.

Miscalculations and follies were not blame-gamed or endlessly litigated, but were instead seen as tragic setbacks on the otherwise inevitable trajectory to victory. When we review their postwar technological achievements—from the interstate highway system and California Water Project to the Apollo missions and the Lockheed SR-71 flights—it is difficult to detect comparable confidence and audacity in subsequent generations. To paraphrase Nietzsche, anything that did not kill those of the Old Breed generation made them stronger and more assured.

As an ignorant teenager, I once asked my father whether the war had been worth it. After all, I smugly pointed out, the “victory” had ensured the postwar empowerment and global ascendance of the Soviet Union. My father had been a combat veteran during the war, flying nearly 40 missions over Japan as the central fire control gunner in a B-29. He replied in an instant, “You win the battle in front of you and then just go on to the next.”   Here….